Lubricant containing calcium salts of acetic acid, c14 to c30 fatty acid, and phosphosulfurized polyolefin



United States Patent 3,2tl2,e06 LUnnrcANr corsrsnsmn CALCIUM SALTS orACETKC ACKD, C T0 C FATTY AQHD, AND

der upon each stroke of the piston by means of a central-,

ized force-feed lubrication system. The lubricant is to a large extentconsumed during each stroke of the piston,

thereby requiring continuous application of the lubricant.

The lubricant should have a fluid, or semi-fluid, consistency 32%,396Patented 24, 1965 treated polymer can result in a calcium acetate typelubricant of exceptional stability and wherein the particlesize of thecalcium acetate is very small, e.g. about 2.0 microns. This smallparticle size allows easy filtration of the fluid lubricant to removeunreactive contaminants (e.g.

silica and aluminum oxide, from commercial lime). The filtered productsare clear, bright and show no haze. It

i has been further found that if the bulk of the dehydration other hand,prior attempts to manufacture calcium acetate.

to permit the lubricant to be readily pumped through the centralizedforced-feed lubrication system and to evenly spread or wet the pistonand cylinder. Another requirement of marine diesel cylinder lubricantsis that they have good antiwear properties. Thus, prevention of wear isvery important due to the giant size of the pistons and cylinders usedin such engines (e.g. piston and cylinder diameters of about 36 inchesare common) since replacement of liners and other worn parts is veryexpensive.

The lubricant should also be storage stable, even when 7 subject to longperiods of storage under hot (e.g. 120 to 140 F.) and vibratingconditions such as frequently occurs during storage in a ships engineroom. The lubricant should also be heat stable so that it does notunduly gel or thicken when moving through hot feed lines or when it hitsthe surface of the hot cylinder.

Lubricants for such marine diesel lubrication, which met the precedingrequirements, have been made by thickening mineral lubricating oil withmixed calcium salts of acetic acid and an intermediate molecular weightfatty acid, e.g. C to C fatty acids. In these prior lubricants, thecalcium acetate salt primarily provided the anti-wear properties, whilethe intermediate molecular weight fatty acid saltsserved primarily asstabilizing agents for maintaining the calcium acetate suitablysuspended in the oil. Due to the short chain length of the intermediatefatty acid salts, their suspending power for the calcium acetate was notas great as desired, with the occasional result that some separation ofoil and salt occurred in storage and in use. This separation led toplugged lines and valves,

and loss of anti-wear properties due to loss of activeingredient.Furthermore, the particle size of the calcium acetate was frequentlylarger than desired for maximum stability. Attempts to improve thestability of the prior calcium acetate type marine diesel lubricantswith soaps of high molecular weight fatty acids, e.g. C C acids,resulted in much better stability but tended to give undesirably viscoussemi-solid to solid lubricants.

It has now been found that improved marine diesel lubricants, superiorin several respects to those made from the intermediate molecular weightfatty acids and acetic acid, can be prepared by using a combination ofhigh molecular weight fatty acid and phosphosulfun'zed polyolefin inplace of part or all of the intermediate molecular Weight fatty acid.This use of high molecular weight fatty acid in combinationwith thesurfactant elfect of the P 5 of the lubricant is carried out in thepresence of free acid- .ity, the phosphosulfurized polyolefin surfactanttends to remain more active, a more fluid lubricant results andformation of less desirable carbonates is minimized. On the typecylinder lubricants using the intermediate fatty acids, whiledehydrating the lubricant on the acid side, (e.g. heating at 225 to 350F.) resultedin undesirably viscous and solid products. Another findingof the present invention is that the combination of ingredients of thisinvention permits forming lubricants superior to said prior intermediatefatty acid type lubricants in having a reduced tendency to gel under hotconditions. This is important in engines which operate at very hightemperatures, where gelling of the lubricant will interfere with thespreading of the lubricant onto the piston and cylinder, and will alsointerfere with pumping the lubricant through hot, narrow diameter, feedlines.

In brief, the compositions of the invention result in a betterdispersion of calcium acetate, greater fluidity, and improvedspreadability" than is obtained by use of th aforesaid priorcompositions.

The higher molecular weight fatty acid used in the present inventionincludes C to C preferably C to C fatty acids. While saturated fattyacids can be used, the unsaturated acids. are preferred. Such preferredfatty acids will include tallow fatty acids, oleic, palmitoleic,gadoleic, erucic, arachidonic, myristoleic acid, etc. These fatty acidsare usually derived from either animal or vegetable sources. In somecases, commercial fatty acid de rived from naturally occurring materialswill contain both saturated and unsaturated acid. For example, somecommercial fatty acids will contain about 40 or even 60 wt. percent ofsaturated fatty acids, with the remainder being principallymono-unsaturated fatty acid along with minor amounts of poly-unsaturatedfatty acid. Trace amounts of lower fatty acid may also be present. Thesemixed saturated and unsaturated fatty acid materials will usually haveWijs iodine numbers of about 35 to 110, preferably 40 to 80, andsaponification numbers of 250 to preferably 225 to mg. KOH/ gm.

. A commercial stabilized fatty acid, available from EmeryIndustries,under the tradename of Emery 636 Fatty Acid, was used inseveral of the working examples of the invention. This acid is acopr-oduct from the dimerization of mono and polyunsaturatedsoya fattyacids. Due to its previous subjection to polymerization, the Emery 636Fatty Acid is so reformed as to be stabilized and potentiallyunpolymerizable. Analysis of this Emery 636 Acid shows the following:

WT. PERCENT ANALYSIS OF EMERY 63 6 The Emery 636 Fatty Acid has thefollowing physical characteristics:

Titer, C. 34-38 Iodine value (Wijs) 55-75 Sapouification valuemg.KOH/gm. 182-205 The phosphosulfurized olefins are well known and areprepared by reacting an olefin or an olefin polymer with P 5 to form amaterial believed to be a dithiophosphoric acid. More specifically, thephosphosulfurized olefins are generally prepared by reacting phosphoruspentasulfide with a polymer of a monoolefin, e.g. an alpha olefin,having 2 to 6 carbon atoms, said polymer having a molecular weight inthe range of 600 to 4,000

Staudinger, preferably 700 to 1400 Staudinger, for about 0.5 to 15 hoursat 150 to 600 F. P 5 treated polybutene is particularly preferred.Preparation of these phosphosulfurized polyolefins is more fullydescribed in US. Patent 2,875,188. The phosphosulfurized polyolefin canbe used per se, or it can be first hydrolyzed. Hydrolyzation is readilycarried out by treating the phosphosulfurized polyolefin with steam tothereby increase the acidity of the phosphosulfurized polyolefin byconverting =8 groups to 4H groups. This hydrolyzation technique andproduct is also well known in the art.

The low molecular weightfatty acid used in the invention will includethose of 2 to 4 carbon atoms such as acetic, propionic, etc. Acetic acidor its anhydride is preferred.

The alkaline earth metal component of the mixed salt composition of theinvention includes calcium, barium, strontium and magnesium, althoughcalcium is preferred. Usually, the acids are neutralized in the presenceof the phosphosulfurized polyolefin with alkaline earth metal base, e.g.a hydroxide, oxide or carbonate. Lime (calcium hydroxide) is preferred.

The oil component of the lubricant is preferably mineral lubricatingoil, although synthetic lubricating oils such as Ucon oils, ester oil,polycarbonate oils, polysilicone oil, etc. can be used.

In general, the lubricants of the invention will comprise a majorproportion of lubricating oil and a minor wear-reducing or thickeningamount of the coneutralized acid mixture of the invention. The finallubricants will generally contain salt of about 1.0 to 10.0 wt. percent,based on the total weight of the lubricating composition, of the mixedfatty acid. Final liquid lubricants for automotive crankcase lubricationor lubrication of marine diesel engine cylinders will generally containsalt of about 3.0 to 10.0 wt. percent of the mixed fatty acid, and saltof about 0.2 to 5.0 wt. percent of phosphosulfurized polyolefin.Preferred final lubricants will contain salt of about 3.0 to 8.0 wt.percent of fatty acid and salt of about 0.2 to 2.0 wt. percent of thephosphosulfurized polyolefin. However, for purposes of economy,concentrates containing salt of 10 to 40 wt. percent, usually 25 to 35wt. percent of the fatty mixture (and salt of a corresponding proportionof phosphosulfurized polyolefin, e.g. about 1.5 to 10 wt. percent willbe first prepared and then later diluted with additional oil to form thefinal lubricant of the invention. These concentrates can also be used assoft greases forgeneral use.

The salt of the fatty acid mixture is preferably formed byconeutralizing, in at least a portion of the oil, about 5.0 to 50,preferably 10 to 35 mole equivalent propor tions of the lower fattyacid, e.g. aceticacid or acetic anhydride, per mole equivalent of thehigher fatty acid material. Thus, the compositioneor concentrate can beprepared by coneutralizing the acids (including the acidicphosphosulfurized polyolefin) in the presence of oil with the alkalineearth metal base, followed by dehydration at a temperature of about 250to 350 F. This dehydration is preferably carried out in .two stepsthefirst dehydration step being on the acid side. This is done by initiallyutilizing an amount of base insufficient to react with all the acidpresent, e.g. to 99 wt. percent of the base required for completeneutralization is used in this initial stage. After dehydrating on theacid side, the lubricant can be made neutral or slightly alkaline by asecond stage reaction involving the addition of a small additionalamount of metal base, followed by further dehydration to evaporate thewater of reaction of this resulting second neutralization. By this twostage process, a more fluid stable final product is obtained.

In the case of marine diesel lubricants, it is frequently desirable thatthe final product have a slight alkalinity in order to better neutralizecorrosive acids formed by the combustion of the fuel oil used in theengine, for example, sulfuric acid formed by the burning of sulfurpresent in the low cost residual fuel oils commonly used to power marinediesel engines.

Good results have been obtained by carrying out the first stage of theneutralization such that the free acidity during the dehydrating step isequivalent to about 0.5 to 3.0 wt. percent as oleic acid, based on thetotal weight of the concentrate. The second stage dehydration ispreferably carried out while the product is neutral or has a slightalkalinity, e.g. 0.05 to 0.3 wt. percent as free sodium hydroxide, basedupon the weight of the concentrate.

High kettle skin temperatures should be avoided during teh aforesaiddehydration steps, since this will tend to cause the finished lubricantto later gel and solidify at elevated temperatures. Thus, when thelubricant base of the invention was prepared in steam jacketed greasekettles at steam pressures of 1l0120 p.s.i., giving kettle bulktemperatures of 300-320 F., excellent products were obtained showing notendency to gel in subsequent oven tests (4 hours at 374 F.). However,when Dowtherm was employed in the kettle jacket, to obtain comparablebulk temperatures (300320 F.) the Dowtherm had to be maintained at 450F. This resulted in finished products which gelled (solidified) whenheated in an oven for 4 hours at 374 F. Lowering the Dowthermtemperature to 350 F. gave excellent non-gelling products, but only amaximum bulk temperature in the grease kettle of 260 F.

Generally, if the alkalinity of the final lubricating composition isincreased too much, the storage stability of .the composition, asmeasured by centrifuge solids, decreases. However, for someapplications, final lubricants having base numbers of about 60 or more,according to ASTM D-66 can be obtained, which are very stable, by apre-centrifuging of the lubricant concentrate during its manufacture.Thus, by making an alkaline concentrate, then centrifuging theconcentrate before it is further blended with additional oil to form thefinished lubricant, the less stably suspended salts are removed from theconcentrate. At the same time, by centrifuging the concentrate, thetotal volume of material requiring centrifuging is much less than if itwas attempted to centrifuge the more dilute finished lubricant.

It will be understood that various minor modifications of the precedingprocedure can be utilized without departing from the inventive scope ofthe invention. For example, preformed alkaline earth metal salt of C toC fatty acid, and/or preformed alkaline earth metal salt of theaforesaid higher fatty acid component can be added to the oil and heatedtogether with the phosphosulfurized polyolefin, orthe alkaline earthmetal salt of the phosphosulfurized polyolefin; Or the phosphosulfurizedpolyolefin or its salt can be added to the composition after the in situneutralization of the C to C fatty acid and the higher fatty acid.However, this latter procedure is not preferred, since it appears toresult in a more viscous product than when the metal salts of the aceticand higher fatty acid are formed in oil in the presence of thephosphosulfurized polyolefin.

Alkaline earth metal salts and soaps of other acids can also beincorporated in the final product, including salts of inorganic acidssuch as phosphoric acid, nitric acid, hydrochloric acid, etc. Thesesalts and soaps can be formed during the neutralization steps previouslynoted, by neutralizing the corresponding acid with the PercentPhenyl-a-naphthylamine 0.2 Mineral lubricating oil of 80 SUS viscosityat alkaline earth metal base. 5 The oil and the bulk of the hydratedlime were mixed ValI S a dltlv s Can e added t the fin lllbfltogether ina steam jacketed grease kettle to form a slurry. cant in amounts of 0.1to 10.0 wt. percent, based on the O -h lf f the Emery acid and /3 of thephosphosul- Welght 0f the filllshed lubricant Among addltlves thatfurized polyisobutylene was added to the kettle. The can be added arecorrosion inhibitors such as sodium nik ttle o te t re mixed andhomogenized by passage trlte, lanohn, W001 grease ti antioxidants suchas through a Charlotte colloidal mill. Then the acetic acidphenyl-ot-naphthylamme; auxlllary eXtfeme Pr ss was slowly added whilemixing and homogenizing while g allXlllflfY antlWear g y etc. keepingthe temperature below 210 F. to prevent boiling. To further improvestability to water contamination as After ll the acetic acid had beenadded, the balance well as further minimizing gelling tendencies at highf the Emery Fatty Acid and the phosphosulfurized temperatures, smallamounts of various surface active polyisobutylene was added while mixingand homogenizagents, including 01056 of the SP normally used as ing.Free acidity determination at this point showed bricating oil detergentadditives, can be added to the final 2 /2 wt. percent, based on thekettle contents, as free composition, usually in amounts of about to 5.0Wt. acidity calculated as oleic acid. The grease mixture was percent.For example, the previously described unne then externally heated whilecontinuing mixing to 300 trallzed phosphosulfurlzed polyolefin can beused. Thus, F, hi h temperature as held for 15 inutes. At the theunneutralized or acidic phosphosulfurized polyolefin end of this time,the free acidity had dropped to 1.2% appears to be effective in prevnting g g, While its as oleic acid. A small amount of additional lime asa alkaline earth metal salt appears to be eifective as a 40 wt. percentlime slurry in mineral lubricating oil was suspendlng agent for the C toC fatty acid salt, e.g. caladded to neutralize the free acidity and togive a free cium acetate. Other useful additives are amino alkylalkalinity as 0.05 wt. percent NaOH. The product was phenols such asthose described in U.S. Patents 2,353,491; then ooled to 250 P, wherethe phenyl-alpha-naphthyland 0. A P ly preferred aamine was added. Theproduct was then further cooled terlal of this type is prepared byreactlng nonyl phenol to 100 F, Mixing by homogenizing was continueddur- With Ethylene diamille and P formaldehyde- Anc'thel' ing the entireprocess including cooling. An excellent recently developed surfaceactive agent is polyisobutylene smooth semi-fluid (at room temperature)product resuccinic anhydride wherein the isobutylene group has a uited,molecular weight of about 700 to 1200, as well as poly- Thephosphosulfurized polyisobutylene in said oil soluamine derivativesthereof, namely amlc acids and imldes tion was prepared by reactingpolyisobutylene of about Obtalned y reacting P l/ p e tetffleth- 800Staudinger molecular weight with 15 wt. percent ylene pentamine, withsaid aforesaid polyisobutylene suc- P 5 based on the weight of thepolyisobutylene at about cinic anhydride. Another preferred material isalkaline 425 F. for about 8 hours under a nitrogen atmosphere. earthmetal petroleum or synthetic alkyl aryl sulfonates of PREPARATION OFFINISHED LUBRICANT about 300 to 700 molecular Weight 25 arts of theconcentrate was mixed with 75 arts The invention will be furtherunderstood by reference p 40 of additional mineral oil. The resuitlngmixture was to the following examples which include a preferred em- Ihomogenized to glve a semi-fluid composltlon having a bodlment of thelnventlon.

40 base number. Example P' f concentrate Comparison product A.'-ExampleI was repeated using A mixed salt concentrate Was prepared having theexactly the same amount of total reactants in the same followingformulation wherein all percents are weight manner except that all thelime was added at one time to percents: the acids, followed bydehydrating at 320 F., so that Percent the entire neutralization wascarried out on the alkaline Glacial acetic acid 16.0 side. e Emery 636Fatty Acid 2.5 Comparison products B, C and D.These products Oilsolution of wt. percent phosphosulfurized 50 were prepared in the mannerof comparison product A but polyisobutylene in 30 wt. percent mineralusing diiferent formulations. lubricating oil 3.0 The compositions andproperties of the preceding com- Hydrated lime 10.2 positions aresummarized in the following table:

TABLE I Example 1 Product A Product B Product 0 Product D Composition(wt. percent) Base Finished Base Finished Base Finished Base FinishedBase Finished Glacialacetlc acid 16.0 4.0 16.0 4.0 16.0 4.00 16.00 4.0010. 00 4. 00 Wecoline AAC acid 8 0. Emery 636 fatty acid 2.5 0.60 2.50.6 3.80 0.95 P 8 polyisobutylenesolutl0n 3.0 .75 3.0 0. 75 4.00 1.00Hydrated lime 10.2 2.55 10.2 a 2.55 10.2 2. 55 10.20 2. 55 10.20 0.55Phenylmaphthylamjne 0.2 0. 05 0.2 0. 05 0.4 0.10 0.40 0.10 0. 20 0.05lVIinerallubricatingoilSOSUS.at2 F 68.1 92.05 68 1 92.05 69.9 92.4069.00 92.40 69.60 92.40

Manufacturing technique A oid Alkaline Alkaline Alkaline Alkali eProperties:

Appearance Excellent Excellent Excellent Excellent Excellent. 4.1 gel tt; t 374 F Fluid Fluid. Gels Gels Fluid. Centrifuge test, percentsediment 4-hr. 0.2% 1.9% 0.8% 10.0 7.0%.

1500 r.p.m. Vise. at F., SSU 1500 1687 1798 2088 1504. Visc. at 210 F.,SSU Q2 96 R 138 Gels 94.6. Ash (S04) wt. percent 4 8 4.8 4 4.9 4.9.4-ball wear scar, mm.'dia. (l kg.l hr.- 0 16 0. 0.27 0.32.

1800 r.p.n1.). Stabilltyinstorage... Good Good. Poor Good. Separates.Lubricator life 100 days 4days Mufie furnace (450 F.) hrs 2.

The 4-hour gel test was carried out by filling an ASTM pour point jar upto mark, which is about Ma full, with the lubricant to be tested. Thetest lubricant is heated for four hours at 374 F. and is cooled for 45minutes. The jar is then examined to see if the lubricant has gelled. Itis seen that the comparison finished lubricant product B, whichrepresents the prior art, had gelled while the finTshed product ofExample I had not. This gelling or lack of gelling is used as anindication of the spreading ability of the lubricant when it hits thehot cylinder it is being used to lubricate. This gel test is also anindication of the lubricants tendency to remain fluid in long feed linesin hot locations.

The centrifuge test was carried out in an ASTM centrifuge and the volumepercent of separated material was reported.

The lubricator life test of Table I was carried out by passing thelubricant under test through a Manzell lubricator at the rate of 2quarts of lubricant a day. The Manzell lubricator includes a sight-glassfilled with an aqueous solution containing 50 wt. percent of a calciumnitrate tetrahydrate as the sight-glass fluid. These lubricators arewidely used in conjunction with marine diesel engines. The lubricatorpermits visual observation of the rate of flow of the lubricant which isforced into the bottom of the sight-glass and then floats up through thehigher density sight-glass fluid to an upper line from where it is thenforced to the cylinder being lubricated. The finished product \ofExample I went for 100 days Without fogging the sight-glass ordisplacing the sightglass fluid. The test was stopped after 100 days. Onthe other hand, the comparison finished lubricant, product B, went foronly 4 days before 75% of the sight-glass fluid had become displaced andthe sight-glass had become sufliciently fogged so as to requiredisassembling and cleaning.

The Mutlle Furnace test was carried out by passing the lubricant at therate of 1 quart a day through a /8 inch, i.d. steel line equipped with aM.A.N. check valve of the type used on marine disel engine lubricatorfeed lines. The check valve and the surrounding portion of the feed linewere maintained at 450 F. inside a mufile furnace. The test ended whenthe valve or line, had become sufficiently plugged to rupture a blow-outpatch in the line set for 300 p.s.i. This test simulates passage of thelubricant through hot diesel engine lubricating feed lines.

In sum, the data of the table shows that the product of the invention(Example I finished) resulted in a lubricant which was very fluid, asindicated by its 1500 SSU viscosity at 100 F., very stable againstsedimentation as measured by the centrifuge test, gave very low wear,was

slow to foul the Manzell lubricator, and had good thermal and storagestability. The data also shows the advantage of the acid technique asopposed to the alkaline tech-" nique (compare Example I and product A);the improvement over the prior art as represented by product B; and

the inability of either the fatty acid alone (product C) or the P 8treated polyisobutylene alone (product D)- to form such excellentlubricants as that of Example I;

Example II In order to further demonstrate the desirablity of util; V

izing the unsaturated high molecular fatty acid as compared to shorterchain saturated fatty acid, representative compositions were preparedaccording to' the technique I. The exact formulations of thesecompositions and TABLE II Formulation. percent wgt:

Glacial acetic acid 4. 00 4 00 Tallow fatty acid 1 0. 63 Wecolinc AAOacids 2 0. 63 P 8 polyisobutylene solution 0. 0. 75 Hydrated limo 2. 552. 55 Phcnyl-a'naphthylamine 0.05 0. 05 Mineral lubricating oil, SUS. at210 F 92. 02 92.02 Properties:

Ash (@1504) percent 4. 80 4. 70 Vise. at F. SUS 1,016 1, 718 Visc. at210 F. SUS 94. 4 101. 4 Centrifuge test, percent so 0.05 0. 35 FluidSolid gel 1 Sap. N0. of 205, Iodine No. 50.

2 Coconut fatty acds consisting of about 46 wt. percent eaprie acid,

about 28 wt. percent eaprylie acid and about 26 wt. percent leuric acid.

3 Same as in Example I.

As seen by Table II, the lubricant of the invention prepared from theunsaturated tallow fatty acid did not gel in the 4-hr. gel test, whilethe comparison lubricant prepared from intermediate molecular weightfatty acids did gel. Also, the greater suspending power of the highermolecular weight tallow fatty acid is noticeable in the relatively lowercentrifuge solids (0.05% vs. 0.35%).

Example III To demonstrate the desirability of utilizing the acidtechnique of the invention, wherein the bulk of the dehydration of theproduct is carried out on the acid side, against the more conventionaltechnique of the prior art wherein the dehydration is carried out on thealkaline side, the following compositions were prepared:

Lubricant A-Preparation of c0ncentrate.-A mixed salt concentrate wasprepared having the following formulation wherein all percents areweight percents:

Percent Glacial acetic acid 16.0 Emery 636 Fatty Acid 2.5

,Oil solution of 70 wt. percent phosphosulfurized polyisobutylene in 30wt. percent mineral lubricating oil (same as in Example I) 3.0

Hydrated lime 10.2

Phenyl-a-naphthylamine 0.2 Mineral lubricating oil of. 80 SUS viscosityat The .oil and the bulk of the hydrated lime were mixed together in asteam jacketed grease kettle to form a slurry. One-half of the Emery 636Fatty Acid and /3 of the phosphosulfurized polyisobutylene solution wasadded to the kettle. The kettle contents were mixed and homogenized bypassage through a Charlotte colloidal mill having an 0.003 opening. Thenthe acetic acid was slowly added while homogenizing and while keepingthe temperature below about 210 F. to prevent boiling. After all theacetic acid had'been added, the balance of the Emery Fatty Acid and thephosphosulfurized polyisobutylene solution 'was'added whilehomogenizing. A free acidity determination at this point showed 3.19 wt.percent based on the kettle contents, as free acidity calculated asoleic acid. The' grease mixture was then externally heated whilecontinuing mixing'to 300 R, which temperature was heldfor about 15minutes. At the end of this time, the free acidity had dropped to 2.34wt. percent as oleic acid. A small amount of additional lime in the formof a 40 wt. percent lime slurry in mineral lubricating oil was added toneutralize the free acidity and to give a free alkalinity of about 0.28wt. percent NaOH. The product was then cooled to 250 F. where thephenyl-alphanaphthylamine was added. The product was then further usedin preparing the inventive composition of Example their properties aresummarized 'in Table II which follows:

cooledto 100 F. Mixing by homogenizing through said Charlotte mill wascontinued during the entire process including cooling. 25 parts of theresulting concentrate was then mixed with 75 parts of additional mineraloil to form the final product which was homogenized again through theCharlotte mill.

' Lubricant B.A concentrate was prepared from the same components aslubricant A, but in a more conventional manner by simply adding the limeto the oil, followed by the addition of the acetic, tallow acid and thephosphosulfurized 'polyisobutylene, which gave a material having a freealkalinity of 0.34 wt. percent as NaOH. The material was then dehydratedat a temperature of 320 F. and the free alkalinity at the finish of thedehydration was 0.29 wt. percent NaOH. The concentrate was then dilutedwith additional oil to form a finished lubricant.

The exact concentrate compositions, the diluted final products andtheproperties of said final products are summarized in Table III whichfollows:

TABLE 111 Lubricant A Lubricant B Concentrate formulation weight):

Glacial acetic acid. Tallow fatty acid 1 Oil sol. of P S polyisobutyleneHydrated lime Phenyl-a-naphthylamine Mineral Lubricating Oil, 80 SUS atFree acidity at start as oleic Free acidity at finish as oleic Freealkalinity at start as NaOH Free alkalinity at finish as NaOH Finishedproduct:

Glacial acetic acid Phenyl-a-naphthylamine Mineral lubricating oil, 80SUS Properties:

sh (S04) percent Via/100 F. SUS Via/210 F. SUS.-. Centrifuge test,percent sediment, 4-

hr. 1500 r.p.m Alkalinity (Wt. percent NaO H) 1 Sap. No. of 205, IodineNo. 50.

The data of Table III indicates preparation of the concentrate in thepresence of free alkalinity (lubricant B) will give higher centrifugesolids indicative of poor stor-' ingredients: Percent Glacial aceticacid 16.0 Animal fatty acid (tallow fatty acid), 2.5 Oil sol. of P 8polyisobutylene (same as in Ex. 1)-- 3.0 O

Percent Hydrated lime 10.2 Phenyl-alpha-naphthylamine 0.2 Mineral oil of80 SUS at 210 F.v 68.1

mill having an 0.003" opening. At this point the free acidity of thecomposition was about 2 wt. percent calculated as oleic acid and basedupon the totalweight of the kettle contents. Heating was then initiatedand the temperature of the mixture was raised to 320 F.'which was heldfor 30 minutes. Next, the free acid was neutralized by the addition of asmall amount of lime, dispersed in oil, to thereby give a finalcomposition having a free alkalinity of 0.05% calculated as NaOH.Cooling was then initiated and the product was cooled to 250 R, wherethe phenyl-alpha-naphthylamine was added as an oxidation inhibitor; Thebase grease wasthen further cooled to 100 F., where it was milled bycirculating from the kettle through a'Charlotte mill and back to thekettle until a smooth homogeneous mass was obtained.

Composition 2.A portion of composition 1 was diluted by mixing withthree times its weight of additional mineral oil to form Composition 2.

Composition 3.A'portion of composition 1 "was cen-i trifuged at 1500rpm. for four, hours which resulted in about 1.5 wt. percent solidseparation. The remaining liquid portion of the lubricant was thenemployed to formcomposition 3 by mixing with three times its weight ofadditional mineral oil. a

Composition 4.A lubricant concentrate was prepared in the same manner ascomposition 1, except that differerent proportions of ingredients wereused.

Composition 5.A portion of composition4 was first centrifuged at 1500rpm. for four hourswhich resulted in 6 percentsolid separation and 94percent liquid portion. The liquid. portion was decanted and dilutedwith additional mineral lubricating oil to form composition 5.Compostion 6.-Composition 6 was prepared by diluting 4 parts ofcomposition 4 with 6 parts of oil.

Composition 7 .This composition was prepared by centrifuginga portion ofcomposition 1 which separated 1.5

percent sediment, then decanting the liquid-portion and diluting 4 partsof the decanted liquid portion with 6 parts of additional oil.

Composition 8.-This composition was prepared by diluting 4 parts ofcomposition 1 with 6 parts of oil.

Theformulations of compositions 1 to 8 and their physical properties aresummarized in Table IV which follows:

TABLE IV.-EFFEGT OF PREOENTRIFUGING Composition Composition (wt.percent):

Glacial acetic acid 16.0 4.0 4. 0 25. 00 6. 25 6. 25 6. 40 6. 40 Tallowfatty acid 2 2. 5 .63 63 2. 50 625 625 1. 00 1.00 Oil sol. P 8po1yis0butylene 3.0 75 3. 00 5 5 1. 20 1. 20 Hydrated lime 10. 2 2. 552. 55 16.00 2. 67 2. 67 4.08 4. 08 Phenyl a-naphthylamine 0. 2 05 05 0.20 03 03 08 08 Mineral lubricating oil of SUS at 210 F 68.1 92. 02 92.0253. 30 87. 24 87. 24 Precentrifuged No 'No Yes N 0 Yes No Yes NoProperties:

Vise. at 100 F., SUS 1, 616 1, 640 1, 618 1, 600 1, 620 Vise. at 210 F.,SUS 94. 4 1- 94' 93 Centrifuge test, percent sediment- 1. 5 0. 45 0. 046.0 0. 40 1. 5 0.20 1.6

4-hr. at 1500 rpm. Base No. ASTMD664 40 40 60 60 v 60 60 Other tests:

4-hr. gel test at 374 F Fluid Fluld Fluid Fluid Fluid Fluid Mufliefurnace at 450 F., hours 18 18+ 18+ 18+ 18 18 1 Approximate compositionbecause of small loss of solids in precentrifuging.

2 Sap. No. of 205, Iodine No. of

As seen by Table IV, composition 1 gave 1.5 percent sediment inthecentrifuge test. Composition 2, which was formed by simply dilutingcomposition 1 with additional oil, gave 0.45 percent sediment.Composition 3, which was prepared by first centrifuging a portion ofcomposition 1 and then diluting, gave only 0.04 percent sediment. Thus,by percentrifuging the concentrate and preparig the final lubricant onlyfrom the decanted portion of the centrifuged material, a more stablefinal product is obtained. By centrifuging the concentrate, the totalmass to be centrifuged is, of course, much less than if the finalproduct were to be centrifuged. Composition 4 shows a concentrateprepared with a much greater amount of salt which gave 6 percentsediment. Upon percentrifuging a portion of composition 4, andthendiluting it back to form composition 5, the resulting composition 5gave only 0.4 percent sediment which is acceptable, and yet a muchhigher base number of about 60 was obtained. On the other hand,compositionv 6 illustrates that if a base number as high as 60 isobtained without percentrifuging the concentrate, the sediment thenbecomes 1.5 percent which is unacceptable. Compositions 7 and 8demonstrate another way of making a higher base numbered product. Inthis-case, by a lesser dilution of composition 1 with percentrifuging,only 0.2 percent sediment was obtained (composition 7). Withoutprecentrifuging, 1.6 percent sediment was obtained (composition 8).

These compositions with base numbers of about 60' have become desirablein some types of engines to pro-v is diluted back to form afinallubricating composition.-

Also, in all cases, compositions were formed which successfully passedthe .4-hr. gel test, and.which were-able to withstand in excess of 18hours in the Muffie Furnace Test, which results indicate stable highquality Example V A grease concentrate was prepared having the followingcomposition:

Percent Glacial acetic acid 16.0 Tallow fatty acid 2.5.

Oil sol. of P 8 polyisobutylene (same as in Example I) 3.0. Hydratedlime 10.2 Phenyl-u-naphthylamine 0.2' Mineral oil 68.1

This grease was preparedby addingthe mineral oil, the hydrated lime, 60%ofthetallow fatty acid, and about /3 of the oil solution ofthephosphosulfurized polyisobutylene to a steam jacketed grease kettle andmixing. To

As demon-- lubricants.

this mixture was added, without external heating, the

acetic acid. After mixing for an additional. /2 hour, the

remainder of the fatty acid and the oil solution .of the.

was being constantly stirred by being pumped and re-" ity in terms ofNaOH. The composition was then cooled to 250 F. where the phenyl-alphanaphthylamine was added followed by cooling to 100 F. The kettlecontents were then passed to storage through the Charlotte mill.

Lubricants a, b, c, and d.The preceding grease concentrate was thendiluted with varying amounts of oil to form different concentrations ofmixed-salt in the final lubricant and consequently to obtain differentbase numbers. In addition, varying amounts of an over-based calciumsulfonate oil solution available under the tradename of Bryton C-300from the Bryton Chemical Company was added to the diluted concentrate.Bryton C-300 consists of about 30% calcium sulfonate having an averagemolecular weight of about 440, about 43.5% mineral lubricating oil andthe remainder is essentially calcium carbonate with a small amount ofcalcium hydroxide. Bryton C-300 has a base number of 300 mg. KOH/gm. Thecalcium sulfonate is prepared from detergent alkylate bottoms, i.e. thebottom fraction obtained after distilla-- tion of benzene alkylated withtetrapropylene.

The compositions prepared and their properties are summarized in Table Vwhich follows:

TABLE V Lubricant a b c d Formulation (Percent \vt.):

Glacial acetic acid 4. 00 6. 40 3. 78 3. 66 Tallow fatty acid 1 0. G31.00 59 57 Oil sol. of P 8 polyisobutylene 0.75 1.20 .70 .68 Hydratedlime 2. 55 4. 10 2. 39 2. 34 1lieiiyl-a-1iaphthylarnine 0. O5 0. 08 0505 Mineral lubricating oil, 80 SUS at 210 02. 02 82. 22 86. 83 84. 45Bryton C-300 5. 66 8.25

Properties:

Vise. at F., SSU 1, 616 1,947 1, 775 1,746 Visc. at 210 F., SSU..- 111.4 98.4 99. 3 4-hr. gel test at 374 F Fluid Fluid i-ball wear scar, mm.dl

hr.-l800 r.p.m.) 0.28 0.28 0.25 0.23 Base No. (ASTM D664) 43. 2 57. 052. 1 62. 2 Centrifuge solids, percent sediment i-hr. 1500 r.p.m 0. 45 10. 40 0 40 1 Sap. No. of 205, Iodine No. of 50.

2 Viscous fluid.

As demonstrated by the data of Table V, Lubricant a shows that arelative low viscosity fluid which does not unduly gel in the gel testcan be obtained with a base number of 43.2. However, withoutprecentrifuging, if the'concentration of the mixed salts is increased toform Lubricant b so as to obtain a higher base number, then a higherviscosity material is obtained wihch tends to gel to form a viscousfluid in the gel test. However, Lubricants c and d demonstrate that highbase numbers can be obtained, the viscosity of the lubricant can be keptrelatively low, and in addition the resulting lubricant will not gel inthe gel test, when using a surfactant such as calcium sulfonate as anadditive.

What is claimed is:

1. A fluid lubricating oil composition suitable for marine dieselcylinder lubrication comprising a major amountof mineral lubricating oiland calcium salts of: (A) about 3 to 10wt. percent of acetic acid and Cto C fatty acid in a relative mole ratio of about 5 to 50 moleequivalent proportions of acetic acid per mole equivalentof C to C fattyacid, and (B) about 0.2 to 5.0

'wt. percent of a phosphosulfurized polymer of a C to .C .monoolefin,said polymer having a molecular weight of about 600 to 4,000 Staudinger.

cycled through a Charlotte mill having, an opening of 0.003" clearance.The product at this stage had a free acidity of 2.26 wt. percent asoleic acid. The material...

was heated to 320 F. and held for /2 hour.

point, the free acidity had decreased to 2.12 wt. percent as oleic acid.Additional lime was then added to neutralize the free acidity and togive 0.13 wt. percent free alkalin- 2. A lubricant according to claim 1,which contains about 0.1 to 5.0 wt. percent of calcium alkylarylsulfonate ..of about 300 to 700 molecular weight. At this 3. Alubricating oil composition according to claim 1,

wherein said C to C fatty acid is a mixed fatty acid having a Wijsiodine number of about 35 to and a saponification number of about to 250mg. KOH/gm.,

said mole ratio is about 10 to 35 mole equivalent of acetic acid permole equivalent of said C to C fatty acid, and said monoolefin ispolyisobutylene.

4. A lubricating oil composition according to claim 3, wherein saidmixed fatty acid is tallow fatty acid.

5. A fluid lubricating oil composition suitable for marine dieselcylinder lubrication comprising a major amount of mineral lubricatingoil and coneutralized calcium salts of: (A) about 3 to 8 wt. percent ofacetic acid and G to C fatty acid having Wijs iodine numbers of about 40to 80 and saponification numbers of about 175 to 225 mg. KOH/gm. in arelative mole ratio of about 10 to 35 mole equivalent proportions ofacetic acid per mole equivalent of C to C fatty acid, and (B) about 0.2to 2.0 wt. percent of a P 8 treated polyisobutylene of about 700 to 1400Staudinger molecular weight.

6. A method of preparing a lubricant concentrate comprisingconeutralizing with lime in mineral lubricating oil, about to 40 wt.percent of acetic acid and C to C fatty acid, in a relative molar ratioof about 5 to 50 molar equivalents of said acetic acid per molarequivalent of said G to C fatty acid, and about 1.5 to 10.0 wt. percentphosphosulfurized polymer of a C to C monoolefin, said polymer having amolecular weight in the range of 600 to 4,000 Staudinger, with about 80to 99 wt. percent of the total amount of lime required for completeconeutralization, heating the resulting mixture to dehydrate saidmixture, then further neutralizing the resulting mixture by the additionof a small amount of additional lime followed by again heating todehydration to form a lubricant concentrate ranging from neutral toslightly alkaline.

7. A method of preparing a lubricant concentrate which comprsiescentrifuging the lubricant concentrate of claim 5 to remove prospectivesediment therefrom, removing the liquid residue, and diluting the liquidresidue with additional mineral oil to form a fluid lubricant containingcalcium salt of about 3 to 10 wt. percent of said acetic and C to Cfatty acids.

8. A method according to claim 7, wherein said G to C fatty acidmaterial contains at least wt. percent of mono-unsaturated fatty acid.

References Cited by the Examiner UNITED STATES PATENTS 2,846,392 8/58Morway et al. 252-40.7 2,875,189 2/59 Sabol et al. 25232.7 2,969,3241/61 Knapp et al. 252--32.7 3,025,238 3/62 Lyons et al. 25232.73,125,521 3/64 Detweiler et al. 252-32.7

DANIEL E. WYMAN, Primary Examiner.

UNITED sTATEs PATENT OFFICE CERTIFICATE OF CORRECTION Patent Nos3,202,606 August 24, 1965 Arnold J Morway et al@ It is hereby certifiedthat error appears in the above numbered patent requiring correction andthat the said Letters Patent should read as corrected below.

Column 14, line 8, for "c.0mpr5i65" read I Comprises line 9, for theclaim reference numeral "5" read M 6 e Signed and sealed this 28th dayof June 1966C (SEAL) Attest:

ERNEST W. SWIDER Attesting Officer Commissioner of Patents EDWARD J.BRENNER

1. A FLUID LUBRICATING OIL COMPOSITION SUITABLE FOR MARINE DIESELCYLINDER LUBRICATION COMPRISING A MAJOR AMOUNT OF MINERAL LUBRICATINGOIL AND CALCIUM SALTS O (A) ABOUT 3 TO 10 WT. PERCENT OF ACETIC ACID ANDC14 TO C30 FATTY ACID IN A RELATIVE MOLE RATIO OF ABOUT 5 TO 50 MOLEEQUIVALENT PROPORTIONS OF ACETIC ACID PER MOLE EQUIVALENT OF C14 TO C20FATTY ACID, AND (B) ABOUT 0.2 TO 5.0 WT. PERCENT OF A PHOSPHONSULFURIZEDPOLYMER OF A C2 TO C6 MONOOLEFIN, SAID POLYMER HAVING A MOLECULAR WEIGHTOF ABOUT 600 TO 4,000 STAUDINGER.